50. __ compounds are twin forms 1,25 points consisting of one basic morpheme (usually the second), sometimes a pseudo -morpheme which is repeated in the other constituent with a different vowel. Reduplicative Ablaut Rhyme

The correct answer is **Reduplicative**.<br /><br />Here's why:<br /><br />* **Reduplicative compounds** consist of two identical or similar morphemes that are repeated with a slight variation, often in the vowel sound. This fits the description provided in the question, where one morpheme (usually the second) is repeated with a different vowel.<br /><br />Let's look at the other options:<br /><br />* **Ablaut:** This refers to a type of vowel change within a single morpheme, not the repetition of morphemes.<br />* **Rhyme:** This generally refers to the repetition of similar sounds in two or more words, often used in poetry and music, but not specifically related to the structure of compounds as described.<br /><br />**In summary:** Reduplicative compounds are formed by repeating a morpheme with slight modifications, which aligns with the description given in the question.